Pulsation-producing device for electrical musical instruments.



M. L. SEVERY & G. B SINCLAIR. PULSATION PRODUCING DEVICE FOR ELECTRICALMUSICAL INSTRUMENTS.

APPLICATION FILED JULY 25, 1907.

1,1 1 1 ,866, Patented Sept. 29, 1914.

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- musicalinstrument timed electric pulsations STATES PATENT oEEIoE.

MELVIN I... SEVERY, or AnLIirG'ron HEIGHTS, AND GEORGE B. SINCLAIR, ornos'ron, mAssAcIIUsEr'rs.

cushion-memoirs :oEvIcE FOR ELECTRICAL MUsIoAnIns'rnUMEN'rs.

Specification of Letters Patent.

Patented Sept. 29, 1914.-

Application filed July 25, 1907. Serial No. 385,456.

To all whom it may concern Be it known that we, MELVIN L. SEVERY, ofArlington Heights, inthe county of Middlesex and Commonwealth ofMassachusetts, and GEORGE B. S1NoLAIR,-of Boston,- in the county ofSufi'olk and said Commonwealth, both citizens of the United States, haveinvented certain new and useful Improvements' in Pulsa't ion-ProducingDevices for Electrical 'Musical Instruments, of which the following is aspecification.

This pulsation producing device is desighed for use in connection withelectric musical instruments wherein tuned.- sonorous bodies arevibrated by means of properly delivered to electromagnets controllingsaid bodies; and our invent-Ion particularly relates to means for Iouping and running the toothed members constituting the major part thedevice, and to improved. means for supporting the brushes cooperatingwith said members.

The drawing formingpart of this specification, is ,a plan view of ourpulsation producing device, with parts thereof broken awa in order tomore clearly reveal others, and other essential features of the electricbeing shown in diagram; I

The reference numeral 1 designates the strin s or other sonorous bodiesvibrated by the e 'ectromagnets 2; 4 is the source of current; 3, thekeys by which the current is switched to any desired electromagnet, and10', the toothed members, preferably metal rings, composing part of thepulsation producing device for rendering the current properly pu satory;operating with said members. As shown in the figure, said members arearranged in groups of twelve-in each group, and as many groups as thereare octaves in the instrument,-preferably six. It is evident that tohave six iu'll octaves it will be necessary for one of theterminal'groups to be supplied .with one extra ring or member.Otherwise, though, the groups may be exact duplicates; each groupcontaining as many members as there are notes in an octave, and thenumb'er of teeth on each member being adapted to the vibrations of someone note of the octave. These groups of mechanically united members aregeared one to the next in a way to cause each group to rotate one halfas fast as the one next 20 being the brushes cogearing also; each groupeach group,

I position permits pulsations ma above it. To do this, the groups areiprcfcrablystaggered sufiiciently to allow a pin,- ion 11 of one groupto mesh with a gear '12 of the group next below, of twice its-pitchline.- Thus the groups will be alike in their having a small gear at oneend and a large gear at the other end. Hence each group of rings orIncinbers 10 will produce electric pulsations numbers per unit of timejust an octave be low those produced by the group next above It; and thestrings I vibrated thereby will be similarly an octave below.

l/Ve prefer to have the fastest turning group of members the one toreceive and transmit power, for the reason that such power it. in theslightest degree varied in speed, Wlll have such variations madeconstantly less noticeable by the repeatedly slower motions of the lowergroups. The means by which power is thusimparted to the fastest groupconsists of the cone and fly-wheel 6, 51, geared thereto; said cone andfly-wheel forming part of any suitable .governing device which forms nopart of the present Invention.

Each group of members can be readily removed from its support by.loosening the nuts 15 and raising the spindle irom.,its confiningpermits of repairs being quickly attended to should need arise.

Above the staggered groups of members is fixeda bar 21 having oblique,lateral faces,

for the support of the brushes contacting with the disks 10. Thesebrushes are held by removable blocks 22 a separate block-for and theblocks are secured to said bar by the turn buttons -23pro'jectingthrough slots said buttons at right angles to their slots, the blocksare fixed in place, while a parallel I the blocks removal.

The circuits through which the electric de by" he niake-and-breakmembers 1.0 are delivered to the electromagnets 2 for the vibration ofthe strings 1 or other sonorous bodies, comprise the following: From thecurrent source 4:, the electricity traverses the wire 32, the frameworkof the machine to the make-andbreak dc vices, thence through spring.contacts 30' and wires 31 of the circuits which have been closed by thedepression of keys 3; associated magnets 2, wires 33, contacts 34,

slots 16 in the standards 17. This 7 24' in the blocks. By turning whichwe brushes 35, and common wire 36 back to said source.

It'is evident that, in an instrument constructed with so many parts asis this, it is of the highest importance both mechanically andcommercially that there shall be so far as possible a duplication of allsimilar elements, anda maximum simplification of de tails inasmuch as aslight complication multiplied a hundred fold will increase the expenseand interfere with the renewal and durability of the instrument to aprohibitive extent. One of the most important of such simplificationsand duplications is that which we have produced in connection with theabove described grouping and staggering of the pulsation producindevices.

Not alone is grouping of members 10 highl important economically, but wefind it to be the most Practical and efiicient Way of roducing per ectlytuned octaves; since sucli groups are duplicates of each other, and areall geared together.

' Althou h the disks 10 and ears 11, 12 all have t eir axes insubstantially the same horizontal plane, we speak of those nearest thesource of power, or cone 6, as above the others because. the higher inrank with respect. thereto. Hence in describin the gearing of the saiddislxs or groups 0 pulsation producing members, we s eak in the claimsof each being geared to t e onenext above it to rotate at one halfthelatters speed. 7

What we claim as our invention and for desire Letters Patent is asfollows, to wit 1. The combination of tuned sonorous bodies, andelectromagnetic means for their vibration embracing a plurality ofsubstantially-duplicate oups of rotative pulsationproducing mem ers, andgears rotatively uniting said members, each of said groups having arotative s ed which is either a multiple or submultiple of some one ofthe other associated groups.

. .772. The combination of tuned sonorous bodies, and electromagneticmeans for their vibration embracing a plurality of substantially dulicate grou s of rotative pulsation pro ucing mem rs, and gearsrotatively uniting said members, the speed of '-bodies,

each of said groups, save the slowest, being amultiple of the speed ofsaid slowest rotating group.

3. The combination of tuned sonorous bodies, and electromagnetic meansfor their actuation having a plurality of substantially duplicate groupsof rotative pulsation producing members geared together to run atrelative speeds which are powers of two.

4. The combination of tuned sonorous and electromagnetic means for theiractuation having a lurality of substantially duplicate groups ofrotative pulsation-producing members each geared to the one next aboveit to rotate at one-half the latters speed.

5. The combination with an electric circuit, of pulsation-producin meanscomprising brushes,.and a plura tially duplicate groups of rotativecurrentaffecting members, each group geared to the one next above it torotate at one-half the latters speed, and each member of a. group beingformed with a number of current-affecting elements.

6. The combination with an electric circuit, of pulsation-producingmeans comprising brushes, and a plurality of substantially duplicategroups of rotative currentafi'ecting members, each group geared to theone next above it to rotate at one-half the latters speed; the power fordriving the same being applied to the fastest rotating group.

7. The combination of tuned sonorous bodies, and electromagnetic meansfor their actuation having a plurality of substantially duplicate groups0 rotative toothed makeand-break members, each group geared to the oneabove it to rotate at one-half the latters speed; the power for drivingthe same being applied to the fastest rotating group.

In testimony that we claim the fore in invention, we have hereunto setour lil ing this 17th day of July, 1907. 7

MELVIN L. sEvERY. GEORGE B. SINCLAIR.

Witnesses:

A. B. UPHAM, CHAS. A. Cnasn.

Copies or um patent may 'be obtained for five cents each, by addressingthe Commissioner of Patents,

' walhlngton, D. C."

ity of substan

